Impacts of Gd-Ce on the structural, morphological and magnetic properties of garnet nanocrystalline ferrites synthesized via sol-gel route

The effect of Gd-Ce substitution on the structural, morphological and magnetic properties of garnet ferrites have been investigated in this study. The nanoferrites of Gd-Ce with different substitution Gd3Ce3-xFe5O12(x = 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0) were prepared using sol-gel route. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Thermogravimetric (TG) and differential thermal (DT) analysis, Fourier transform infrared (FTIR) and Vibrating sample magnetometer (VSM) were used to measure the characteristics of Gd-Ce substituted nanocrystalline powders. X-ray diffraction analysis revealed single phase structure of Gd-Ce substituted garnet ferrites. However, lattice constant was not increased by increasing the Ce3+ contents in the garnet structure which may be due to the non-replacement of Fe(3+)ions. FTIR and TGA also confirm the garnet phase and nanocrystalline nature of Gd-Ce substituted garnets respectively. Gd substituted ferrite without Ce3+ contents shows better homogenous structure with well crystalline grains. The average particle size was in the range of 80-98 nm for all Gd-Ce substituted nanocrystalline samples. Magnetic saturation, magnetic remanence, coercivity, Bohr magneton and magneto crystalline anisotropy constant (K) were calculated from MH loops. It is noticed that the saturation magnetization, remanence decreased as concentration of Ce3+ increased from x = 0 to x = 1.0 whereas at x = 1.5 the saturation and remanence increased. Super paramagnetic behaviour was observed for Gd substituted ferrites. Furthermore, increase in coercivity in Gd-Ce substituted nanocrystalline was observed from x = 0 to x = 2.5 whereas coercivity decreased at x = 3.0. These Gd-Ce substituted nanocrystalline garnet ferrites may play an important role for variety of applications. (C) 2015 Elsevier B.V. All rights reserved.